JP2992485B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply heat exchanger for heating water supplied from a water supply path and supplying the same to a hot water supply path, and one type of heating means for heating the hot water supply heat exchanger and another heat exchanger. A burner, a bypass which connects the water supply path and the hot water supply path in a state of bypassing the heat exchanger for hot water supply, and a mixing means for mixing water from the bypass path and hot water from the heat exchanger for hot water supply. Control means for controlling the operation of the mixing means,
A hot water supply device configured to control the mixing means so as to supply a hot water at a target temperature by adjusting a mixing ratio of water from the bypass passage and hot water from the hot water supply heat exchanger; About.

[0002]

2. Description of the Related Art A hot water supply apparatus in which a heat exchanger for hot water supply and another heat exchanger, for example, a heat exchanger for heating, are heated by one burner has been known. In the hot water supply apparatus having such a configuration, when the burner is burned during the heating operation, the hot water supply heat exchanger is also heated at the same time even during the hot water supply operation, and the temperature of the hot water in the hot water supply heat exchanger becomes high. In such a state, if the hot water supply operation is performed during the heating operation, after the heating operation is completed, or the like, high-temperature hot water is supplied at the start of the hot water supply operation, resulting in a dangerous state. Therefore, in the related art, one bypass path that bypasses the hot water supply heat exchanger is provided, and a mixing valve that mixes the water from the bypass path with the hot water from the hot water supply heat exchanger is provided. At the start, the mixing valve is greatly opened to the bypass path side to mix a large amount of water from the bypass path.

[0003]

However, in the conventional hot water supply apparatus, only one bypass path is provided and, naturally, only one mixing valve. Therefore, the mixing valve is connected to the heat exchanger for hot water supply. If a failure occurs in the open state, hot water may be unexpectedly supplied at the start of hot water supply, and there is room for improvement in this respect.

The present invention focuses on such a conventional problem. The purpose of the present invention is to provide a hot water supply system even if a mixing means such as a mixing valve fails while being open to the hot water supply heat exchanger. It is an object of the present invention to provide a hot water supply device that can prevent hot water from being supplied at the start.

[0005]

In order to achieve this object, according to the first aspect of the present invention, a water supply path and a hot water supply path are added to a bypass path connecting the hot water supply heat exchanger in a bypass state. Further, an auxiliary bypass path that connects the water supply path and the hot water supply path in a state of bypassing the hot water supply heat exchanger is provided,
Also, a bypass valve is provided to interrupt the flow of water through the auxiliary bypass passage, and at the start of hot water supply, the control means controls the mixing means and the bypass valve so as to supply water to the hot water supply passage through the bypass passage and the auxiliary bypass passage. Even if the mixing unit that mixes the water from the bypass and the hot water from the hot water supply heat exchanger breaks down in the open state toward the hot water supply heat exchanger, Since the water is supplied from the auxiliary bypass path to the hot water supply path and mixed with the hot water from the hot water supply heat exchanger, unexpected supply of hot water at the start of hot water supply is avoided.

According to the second aspect of the present invention, there is provided a temperature detecting means for detecting a temperature of hot water from the hot water supply heat exchanger, and the control means sets the temperature detected by the temperature detecting means in advance. Since the bypass valve is closed as the temperature becomes lower than the temperature, after reliably closing the bypass valve while avoiding the supply of hot water having a temperature higher than the preset temperature, Hot water at a desired temperature can be supplied by controlling the mixing means by the control means.

According to the third aspect of the present invention, since the auxiliary bypass path is connected to the hot water supply path downstream of the mixing means, it is possible to prevent hot water from being unexpectedly supplied at the start of hot water supply. While avoiding, it becomes possible to supply hot water at a desired temperature in a relatively short time. That is, the auxiliary bypass passage may be connected to the hot water supply passage on the upstream side of the mixing means. In this case, if an attempt is made to avoid the supply of hot water at the start of hot water supply, the amount of water from the auxiliary bypass passage is reduced. It is necessary to open the mixing means to the hot water supply heat exchanger side, that is, to make the mixing ratio of the mixing means uneven. Therefore, if the bypass valve is subsequently closed to obtain hot water having a desired temperature by controlling the mixing means, it takes time until the mixing ratio is adjusted by the mixing means. In that regard, if the auxiliary bypass is connected to the downstream side of the mixing device, the amount of water from the auxiliary bypass can be ensured regardless of the mixing ratio of the mixing device, so that the mixing ratio of the mixing device is biased. It is not necessary to keep the ratio, and hot water at a desired temperature can be supplied in a short time by adjusting to a desired mixing ratio.

According to the fourth aspect of the present invention, the water proportional valve is provided in the hot water supply passage downstream of the mixing means and upstream of the connection point between the auxiliary bypass passage and the hot water supply passage. Therefore, even if the mixing means for adjusting the mixing ratio between the water from the bypass and the hot water from the hot water supply heat exchanger breaks down, the water proportional valve allows a certain degree of temperature adjustment. That is, when the water proportional valve is provided downstream of the mixing means and downstream of the connection point between the auxiliary bypass path and the hot water supply path, the mixing means cannot operate with a certain mixing ratio. Then, even if the flow rate is adjusted by the water proportional valve, only the flow rate can be adjusted, the mixing ratio of hot water and water becomes constant, and the hot water temperature cannot be adjusted. In that regard, by providing the water proportional valve upstream of the connection point between the auxiliary bypass path and the hot water supply path, the water proportional valve maintains the water flow from the auxiliary bypass path at a substantially constant level. The flow rate of the mixture of the hot water and the hot water from the hot water supply heat exchanger can be adjusted, and as a result, the mixing ratio of the hot water and the water can be adjusted and the temperature of the hot water can be adjusted to some extent, improving usability. .

According to a fifth aspect of the present invention, the mixing means is a mixing valve, and the control means adjusts and controls the mixing valve to a preset opening before starting hot water supply. Therefore, by setting the set opening of the mixing valve close to the opening frequently used during normal operation, hot water at a desired temperature can be quickly supplied.
Since the control means controls the opening of the bypass valve before the start of hot water supply, it is avoided that hot water is unexpectedly supplied at the start of hot water supply.

[0010] According to the invention described in claim 6, the other heat exchanger is a heating heat exchanger for heating hot water for a heater, and the heat transfer tube and the hot water supply heat of the heating heat exchanger. Since the heat transfer tubes of the exchanger share the same heat transfer plate, the structure can be simplified by sharing the heat transfer plate, and
With the interposition of the heat transfer plate, the position setting between the heat transfer tube of the heating heat exchanger and the heat transfer tube of the hot water supply heat exchanger becomes easy.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a water heater according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the hot water supply apparatus includes a hot water supply heat exchanger 1 and a heating heat exchanger 2, and a heat transfer tube 3 and a heating heat exchanger 2 of the hot water supply heat exchanger 1.
Are connected to each other by a plurality of common heat transfer plates 5, and the heat transfer tubes 3 and 4 share the same heat transfer plate 5. The heat exchanger 1 for hot water supply and the heat exchanger 2 for heating are:
A fan 7 that is configured to be heated by one gas-fired burner 6 and that supplies combustion air to the burner 6 is also provided.

The heat transfer pipe 3 of the hot water supply heat exchanger 1 is connected to an ordinary household water pipe to supply water for heating, and the heated hot water is supplied to a bathtub or hot water supply (not shown). A hot water supply path 9 for supplying water to the tap is connected, and a water supply path 8 is provided with a water amount sensor 10 for detecting a water flow rate and a water supply thermistor 11 for detecting a temperature of water supplied to the heat exchanger 1 for hot water supply. Is provided with a tapping thermistor 12 as temperature detecting means for detecting the temperature of the hot water after heating.

The water supply path 8 and the hot water supply path 9 are connected to each other by two bypass paths, that is, a mixing bypass path 13 and an auxiliary bypass path 14 that bypass the hot water supply heat exchanger 1. At the connection point between the path 13 and the hot water supply path 9, the mixing ratio between the amount of hot water from the hot water supply heat exchanger 1 and the amount of water from the bypass path 13 is adjusted to obtain hot water having a desired temperature. Mixing valve 15 as mixing means
Is provided. The auxiliary bypass passage 14 is provided with a solenoid valve 16 as a bypass valve for interrupting the flow of water, connected to the hot water supply passage 9 downstream of the mixing valve 15, and connected to the hot water supply passage 9 downstream of the connection point. The hot water supply thermistor 17 for detecting the temperature of the hot water mixed by the mixing valve 15 and the water proportional valve 18 for adjusting the flow rate
Are provided.

As shown in FIG. 2, the mixing valve 15 includes a valve body 20 housed in a casing 19 and a valve body 20.
And a shaft 22 for interlockingly connecting the valve element 20 and the actuator 21. The actuator 21 reciprocates the valve element 20 in the left-right direction in the drawing to provide a hot water supply path. It is configured to adjust the mixing ratio of the amount of hot water from No. 9 and the amount of water from the bypass passage 13. It should be noted that the mixing ratio of the mixing valve 15, that is, the amount of hot water / (the amount of hot water + the amount of water) and the operating position of the valve element 20 have a relationship as shown in FIG.

The heat transfer pipe 4 of the heating heat exchanger 2 has a heating water supply passage 24 for supplying hot water in a heating expansion tank 23 and a heating hot water supply passage 25 for supplying heated water. The heating hot water supply passage 25 is connected to a heat exchanger of various heaters such as a bathroom heater / dryer and a floor heater not shown. The heat exchanger of the heater includes a return path 26 for heating.
Is connected, and the hot and cold water after the heat exchange by the heat exchanger of the heater is returned to the expansion tank 23 through the heating return path 26.

The heating water supply passage 24 has an expansion tank 2
A circulating pump 27 is provided for sucking water from the inside 3 and supplying it to the heating heat exchanger 2 and for supplying heated water to a heater (not shown). A heating thermistor 28 for detecting the temperature of hot water later is provided. The heating hot water supply path 25 and the heating return path 26 downstream of the heating thermistor 28 are connected to each other by a heating bypass path 29 that bypasses a heater (not shown). An electromagnetic on-off valve 30 for interrupting the flow of hot water is provided in the heating hot water supply passage 25 on the downstream side.
Is provided.

The burner 6 is configured to be supplied with fuel gas for general household use, and includes a safety valve 31 for intermittently supplying fuel gas and an electromagnetic gas proportional valve 32, which is an original gas supply passage 33. Are connected to two gas supply paths 34 and 35, respectively, and the gas supply paths 34 and 35 are provided with gas switching solenoid valves 36 and 37, respectively. That is, the burner 6 is provided with two combustion blocks, one of which is connected to the gas supply path 34 and the other to the other gas supply path 35, and as shown in FIG. It is configured to be switchable between a state of combustion capacity 1 for burning and a state of combustion capacity 2 for burning both combustion blocks. In FIG. 4, the horizontal axis indicates the input amount of the burner 6, and the vertical axis indicates the rotation speed of the fan 7.

The operation of the hot water supply apparatus is controlled by a control section H, which is a control means mainly including a microcomputer, and includes an operation switch 38 and a temperature for setting a hot water supply temperature during hot water supply operation. A remote controller R having a setting switch 39 and the like is connected. When the operation switch 38 of the remote controller R is turned on, the operation is enabled, and a hot water supply operation is executed by opening a hot water tap (not shown).
The heating operation is executed by turning on the switch of the heater outside the figure.

During the hot water supply standby state prior to the hot water supply operation, the water proportional valve 18 of the hot water supply passage 9 is maintained in the open state, and as shown in the flowchart of FIG. 16 is maintained in an open state, and the opening of the mixing valve 15 is maintained at a preset opening. Specifically, the mixing ratio represented by hot water amount / (hot water amount + water amount) is set to about 0.5, that is,
The valve element 20 of the mixing valve 15 is maintained at the position indicated by P1 in FIG. Therefore, even if a hot water tap (not shown) is opened in a state where hot water exists in the heat transfer tube 3 of the heat exchanger 1 for hot water supply, the hot water supply path 9 is connected to the hot water supply path 9 via the bypass path 13 and the auxiliary bypass path 14. Since water is supplied, hot water is not discharged from the hot water tap.

Then, when the water amount sensor 10 detects that a predetermined amount or more of water has passed through the water supply passage 8, and when the temperature detected by the tapping thermistor 12 becomes lower than a preset temperature, for example, 60 degrees Celsius. The hot water supply operation is executed while closing the solenoid valve 16 of the auxiliary bypass passage 14 and adjusting the opening of the mixing valve 15. In this hot water supply operation, the fan 7 is driven to rotate at a predetermined rotational speed for prepurge, and FIG.
As shown in the flowchart, the burner 6 is ignited by an igniter (not shown). At the time of this ignition, the safety valve 31 of the original gas supply path 33 and the two gas supply paths 34, 35
The gas switching electromagnetic valves 36 and 37 are opened, and the gas proportional valve 32 is adjusted to the opening for ignition, and the ignition is performed in the state of the combustion capacity 2 shown in FIG.

When the ignition of the burner 6 is detected by a frame rod (not shown), the temperature setting switch 3 of the remote controller R
The required combustion capacity of the burner 6 is calculated based on the temperature set by the control unit 9, the water supply temperature detected by the water supply thermistor 11, the water flow detected by the water amount sensor 10, and so-called feedforward control is executed. If the calculated required combustion capacity is 15,000 kilocalories or more per hour, 15.0
If the calorie is less than 00 kcal, one of the gas switching solenoid valves 37 is closed to burn the burner 6 with the combustion capacity of 1, and the opening of the mixing valve 15 is adjusted.
Control is performed such that hot water at the temperature set by the temperature setting switch 39 is discharged.

During this hot water supply, the hot water supply thermistor 1
7, the hot water supply temperature is detected, and based on the detected temperature, the openings of the gas proportional valve 32 and the mixing valve 15 are adjusted, and so-called feedback control is also executed.
When the combustion capacity becomes 20,000 kcal or more per hour during the combustion with the combustion capacity 1, the state is switched to the combustion capacity 2, and conversely, during the combustion with the combustion capacity 2, the state becomes less than 15,000 kcal. Then, the state is switched to the combustion capacity 1 and the combustion is continued. When the hot-water tap is closed and the amount of water flow detected by the water amount sensor 10 becomes equal to or less than the set amount, the safety valve 31 and the gas switching solenoid valves 36 and 3 are provided.
The valve 7 is closed to stop combustion, post-purge is executed and hot water supply ends, and the system returns to the hot water supply standby state described above.

In the heating operation, the circulation pump 27 is driven, and the burner 6 is burned by the same operation as in the above-described hot water supply operation. At this time, the on-off valve 30 is maintained in the closed state, and the hot water heated by the heating heat exchanger 2 is returned into the expansion tank 23 via the heating bypass 29 and the heating return passage 26. Therefore, even if hot water exists in the heat transfer tube 4 of the heating heat exchanger 2, the hot water is not directly supplied to the heater. And heating thermistor 2
When the temperature detected by the heater 8 reaches a predetermined temperature, or after a certain period of time, the on-off valve 30 is opened, hot water of a predetermined temperature is supplied to the heat exchanger of the heater, and the heater is turned off. The combustion operation of No. 6 stops, and the heating operation ends.

[Alternative Embodiment] The hot water supply apparatus may be configured as shown in FIG. 7 in addition to the embodiment shown in FIG. The hot water supply devices according to these two embodiments have almost the same configuration, and only the differences will be described. In the embodiment of FIG. 1, a water proportional valve is provided in the hot water supply passage 9 downstream of the connection point between the auxiliary bypass passage 14 and the hot water supply passage 9. In the embodiment of FIG. 7, the water proportional valve 18 is provided upstream of the connection point between the auxiliary bypass path 14 and the hot water supply path 9 and downstream of the mixing valve 15. It is provided in.

In the hot water supply apparatus shown in FIG. 7, by adjusting the opening of the water proportional valve 18, the amount of water from the auxiliary bypass passage 14 is not changed so much, but is mixed by the mixing valve 15. Since the amount of hot water can be freely adjusted, the mixing ratio can be adjusted as shown in FIG. In other words, when the mixing valve 15 fails to open to the hot water supply path 9 side, in the hot water supply apparatus of FIG. 1, opening the bypass valve 16 can prevent hot water from being supplied, but the mixing ratio becomes constant. Although the mixing ratio does not change even if the degree of opening of the water proportional valve 18 is adjusted, in the hot water supply device of FIG. 7, the amount of water from the auxiliary bypass passage 14 is maintained substantially constant by adjusting the degree of opening of the water proportional valve 18. Since the amount of hot water from the hot water supply heat exchanger 1 can be adjusted, the mixing ratio can be adjusted.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of the entire hot water supply apparatus.

FIG. 2 is a schematic configuration diagram of a mixing valve.

FIG. 3 is a graph showing mixing characteristics of a mixing valve.

FIG. 4 is a graph showing combustion characteristics of a burner.

FIG. 5 is a flowchart showing an operation at the start of hot water supply.

FIG. 6 is a flowchart showing operations during a hot water supply operation and a heating operation.

FIG. 7 is a configuration block diagram of an entire hot water supply apparatus showing another embodiment.

FIG. 8 is a graph showing mixing characteristics according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger for hot water supply 2 Heat exchanger for heating as another heat exchanger 3 Heat transfer tube of heat exchanger for hot water supply 4 Heat transfer tube of heat exchanger for heating 5 Heat transfer plate 6 Burner 8 Water supply path 9 Hot water supply path 12 Temperature detecting means 13 Bypass path 14 Auxiliary bypass path 15 Mixing valve as mixing means 16 Bypass valve 18 Water proportional valve H Control means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiken Kanoto, 1-15-1 Oka, Minami-shi, Minato-ku, Osaka City, Osaka Prefecture (72) Inventor Nobuaki Teshima 1-1-1, Oka, Minami-shi, Minato-ku, Osaka, Osaka No. 52, Harman Co., Ltd. (72) Inventor Hirosao Iida 1-152 Oka, Minami-ku, Minato-ku, Osaka-shi, Osaka Herman-Co., Ltd. ) Surveyed field (Int.Cl. ⁶ , DB name) F24D 3/08 F24H 1/00 604

Claims (6)

(57) [Claims] 1. A hot water supply heat exchanger for heating water from a water supply path and supplying the same to the hot water supply path, one burner for heating the hot water supply heat exchanger and another heat exchanger, and the water supply path And a hot water supply path are connected to bypass the hot water supply heat exchanger, mixing means for mixing water from the bypass path with the hot water from the hot water supply heat exchanger, and operation of the mixing means Control means for controlling the mixing means to adjust the mixing ratio of water from the bypass passage and hot water from the hot water supply heat exchanger to supply hot water at a target temperature. A hot water supply apparatus configured to perform the following steps: an auxiliary bypass path that connects the water supply path and the hot water supply path in a state of bypassing the hot water supply heat exchanger, in addition to the bypass path; A bypass valve for interrupting water flow; , Configured and Aru water heater to control the mixing means and the bypass valve to supply water to the hot water supply passage through the bypass passage and the auxiliary bypass during start hot water. 2. A temperature detecting means for detecting a temperature of hot or cold water from the hot water supply heat exchanger, wherein the control means detects that the temperature detected by the temperature detecting means falls below a preset temperature. The hot water supply device according to claim 1, wherein the bypass valve is configured to close. 3. The hot water supply apparatus according to claim 1, wherein the auxiliary bypass path is connected to a hot water supply path downstream of the mixing unit. 4. The hot water supply apparatus according to claim 3, wherein a water proportional valve is provided in a hot water supply path downstream of the mixing means and upstream of a connection point between the auxiliary bypass path and the hot water supply path. . 5. The mixing means is a mixing valve, and the control means adjusts and controls the mixing valve to a preset opening before starting hot water supply, and controls the opening of the bypass valve. The hot water supply device according to any one of claims 1 to 4, which is configured. 6. The other heat exchanger is a heating heat exchanger for heating hot water for a heater, and a heat transfer tube of the heating heat exchanger and a heat transfer tube of the hot water supply heat exchanger are provided. The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus shares the same heat transfer plate.